Quantum mechanicsLesson 2 of 4 in the course Atomic Structure

Electron Spin: Magnetic Moments, Coupling, and Hydrogen Structure

5 flashcards · 5 quiz questions · 5 match pairs · 5 fill-in sentences · English

Save course
Lesson progress
0 / 5

Your progress is kept in this browser only.Sign up to save it

Summary

Electron spin is an intrinsic form of angular momentum that gives an electron magnetic properties. This lesson introduces the spin quantum numbers, the two possible spin orientations of an electron, and how an external magnetic field separates their energies.

Spin is an intrinsic characteristic of particles, rather than the motion of a particle along an orbit. Although it is sometimes compared with a spinning object, quantum spin is a fundamental property and does not mean that an electron is literally a tiny rotating sphere.

All flashcards

What is electron spin?
Electron spin is intrinsic, quantized angular momentum; it does not mean the electron is a tiny rotating sphere.
What values can the electron spin projection quantum number take?
ms=+12m_s=+\frac{1}{2} and ms=−12m_s=-\frac{1}{2}, corresponding to spin-up and spin-down.
How is the electron's spin magnetic moment oriented relative to its spin angular momentum?
The magnetic-moment vector points opposite to the spin angular-momentum vector.
What causes fine structure through spin-orbit coupling?
Interaction between the spin magnetic moment and the magnetic field associated with orbital motion.
What interaction produces hydrogen hyperfine structure?
Interaction between the magnetic moments of the electron and proton.

Quiz questions

  1. Which interaction contributes to fine structure in hydrogen by coupling spin to orbital motion?Answer: Spin-orbit coupling
  2. Why does the Stern–Gerlach apparatus use a nonuniform magnetic field to separate a beam of silver atoms?Answer: The field gradient exerts a net force that deflects magnetic dipoles.
  3. In hydrogen, what interaction produces the small energy splitting called hyperfine structure?Answer: Interaction between the electron's and proton's magnetic moments
  4. Approximately what wavelength is associated with the hydrogen 21-centimeter line?Answer: 21 cm21\,\mathrm{cm}
  5. How do astronomers use the hydrogen 21-centimeter line?Answer: To trace hydrogen gas and map galactic structure

Based on University Physics Volume 3 by Samuel J. Ling, Jeff Sanny, William Moebs (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.

More in Quantum mechanics

All Quantum mechanics lessons
Quantum mechanicsDe Broglie Matter Waves: Relations, Quantization, and Diffraction5 flashcards · 5 quiz questions · 4 gamesPlay free →Quantum mechanicsHydrogen Atom: Quantum States, Angular Momentum, and Probability5 flashcards · 5 quiz questions · 4 gamesPlay free →Quantum mechanicsQuantum Wave Functions: Probability, Measurement, Operators, and Symmetry5 flashcards · 5 quiz questions · 4 gamesPlay free →Quantum mechanicsTime-Dependent and Time-Independent Schrödinger Equations5 flashcards · 5 quiz questions · 4 gamesPlay free →Quantum mechanicsQuantum Harmonic Oscillator: Energy Levels and Wave Functions5 flashcards · 5 quiz questions · 4 gamesPlay free →Quantum mechanicsPhotoelectric Effect: Photons, Thresholds, and Stopping Potential5 flashcards · 5 quiz questions · 4 gamesPlay free →